I'm working on an old Sovtek Mig 50. It's almost all original and it sounds great now that I've touched up some bad solder joints. While testing around in the amp I noticed on a few filter caps and a few resistors (all within the B+ line) I'm able to read anywhere from 125 to 350 dcv through the side walls of the components. When doing this on a couple resistors it'll make the amp screech horribly. I'm guessing this is a sure sign of faulty/leaky components. Though I'm getting accurate resistances and the B+ is what I would expect with this amp.
Just curious what anyone might know about this.
I can post photos if that is at all helpful.
Just curious what anyone might know about this.
I can post photos if that is at all helpful.
Touching the odd resistor and it makes odd sounds is due to spurious noise generated by the load and feedback from the test lead used. One cannot test a resistance whilst powered with large amounts of DC. They must be tested when cold and totally discharged. Even then one may get incorrect readings.
What kind of voltmeter are you using? Some voltmeters have extremely high input impedance, which means that they can 'see' voltage through low-grade insulation. My old Keithley 2000, for instance, has 10 gigohm input Z on the lower DC voltage ranges.
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